As their name suggests, these are the most widespread of pinnipeds.

Life span
Male common seals have a shorter life span than females, living up to 20-25 years as opposed to females living up to 30-35 years. This is probably due to the stresses incurred by males during the breeding season.

Statistics
Males (bulls): 1.4-1.9m, 55-170 kg, Females (cows): 1.2-1.7m, 45-105 kg.

Physical description
Common seals vary in colour from black, brown, grey or tan, with darker patches. The pattern is unique to the individual. They have a relatively large head with a short body and flippers.

Distribution
Common seals are the most widely distributed pinniped, and there are thought to be about 400,000-500,000 individuals. They inhabit the waters of the north Atlantic and north Pacific Oceans.

Diet
They are opportunistic feeders and hunt fish, molluscs and crustaceans. They make short regular dives, usually to less than 100m.

Behaviour
Common seals haul out onto rocky shores, mud flats and sandy beaches. They may also inhabit fresh water. They do not tend to travel more than 20km from the shore.

Common seals are gregarious, although they do not tend to gather in such large groups typical of other pinnipeds. Killer whales, polar bears and Steller sea lions will hunt common seals, and pups may fall victim to foxes and large birds of prey.

Reproduction
Courtship and mating take place underwater and females give birth to a single pup. The pup is born in an advanced state of development, and can crawl and swim within a few hours of birth. The mother will mate again immediately after weaning.

Conservation status
Common seals are not endangered, although their habit of staying in the same area for the majority of the year has meant that some local populations have disappeared. As with most pinnipeds, there is conflict with fishermen.

Seals can become entangled and drown in fishing nets, and in the UK, Canada and Norway, it is legal to shoot any seals that come near fisheries. It is illegal to commercially hunt common seals, but some hunting for subsistence still occurs.